无法在ModelPopUpExtender

Question

我正在使用ModelPopUpExtender，以便在单击按钮时生成弹出框。我把按钮放在桌子里面。以下代码有什么问题？我通过直接调用DIV标记做了同样的事情。它完美的工作。当我在表格元素中添加按钮时，会出现以下问题。

<cc1:ModalPopupExtender ID="mp1" runat="server" PopupControlID="Panl1"
TargetControlID="unlockbutton"
CancelControlID="Button2" BackgroundCssClass="Background">
</cc1:ModalPopupExtender>
<asp:Panel ID="Panl1" runat="server" CssClass="Popup" align="center"
style = "display:none">
<iframe style=" width: 350px; height: 300px;" id="irm1"
src="PopUp.aspx"  runat="server"></iframe>
</asp:Panel>

    <asp:ListView runat="server" ID="ResultsListView"
    DataKeyNames="PatientCompletedID"
    OnItemCommand="ResultsListView_ItemCommand">
    <LayoutTemplate>
        <fieldset class='ui-widget-content'>
            <legend>Results</legend>
            <table id="results"> 
                <tr>    
                    <td class="ui-state-active">Col1</td>
                    <td class="ui-state-active">Col2</td>
                    <td class="ui-state-active">Col3</td>
                    <td class="ui-state-active">Col4</td>
                    <td class="ui-state-active">Col5</td>
                    <td class="ui-state-active">Col6</td>
                    <td class="ui-state-active">Col7</td>
                    <td class="ui-state-active">Col8</td>
                </tr>
                <asp:PlaceHolder ID="itemPlaceholder" runat="server">
    </asp:PlaceHolder>
            </table>
        </fieldset>
    </LayoutTemplate>
    <ItemTemplate>
        <tr>
            <td style="text-align:left;"><%#Eval("Col1") %></td>
            <td style="text-align:left;"><%#Eval("Col2") %></td>
            <td><%#Eval("Col3")%></td>
            <td><%#Eval("Col4")%></td>
            <td><%#Eval("Col5","{0:d}")%></td>
            <td><%#Eval("Col6","{0:MM/dd/yyyy hh:mm:ss}")%></td>
            <td><%#Eval("Col7")%></td>
            <td><asp:Button CssClass="ui-button ui-widget ui-state-
            default ui-corner-all ui-button-text-only" 
                            runat="server" 
                            ID="unlockbutton" 
                            CommandName="unlock"
                            CommandArgument="unlock"
                            Text="Unlock"></asp:Button>
            </td>
        </tr>
    </ItemTemplate>
    <AlternatingItemTemplate>
    <ItemTemplate>
        <tr style="background:white">
            <td style="text-align:left;"><%#Eval("Col1") %></td>
            <td style="text-align:left;"><%#Eval("Col2") %></td>
            <td><%#Eval("Col3")%></td>
            <td><%#Eval("Col4")%></td>
            <td><%#Eval("Col5","{0:d}")%></td>
            <td><%#Eval("Col6","{0:MM/dd/yyyy hh:mm:ss}")%></td>
            <td><%#Eval("Col7")%></td>
            <td><asp:Button CssClass="ui-button ui-widget ui-state-
            default ui-corner-all ui-button-text-only" runat="server"
            ID="unlockbutton" CommandArgument="unlock" Text="Unlock">
    </asp:Button></td>
        </tr>
    </ItemTemplate>        
    </AlternatingItemTemplate>
    <EmptyDataTemplate>
        <div style="color:Red">No results found</div>
    </EmptyDataTemplate>
 </asp:ListView>